CDKN2A and infection: Similar to the Syrian hamsters, signs of cellular senescence, including expression of p16INK4a and p19ARF (critical inducers of cellular senescence encoded by the CDKN2A gene) and SASP factor genes, were increased at day 14 after infection in the lung, when SARS-CoV-2 became hardly detectable in BALB/c mice (Extended Data Fig. 10).